Adrenal Insufficiency – Causes, Symptoms and Treatment

What Is Adrenal Insufficiency?

Adrenal insufficiency, sometimes informally referred to as adrenal weakness or adrenal fatigue, is a medical condition in which the adrenal glands fail to produce adequate amounts of essential hormones — primarily cortisol, but also aldosterone and adrenaline. The adrenal glands are two small, triangular glands located above each kidney. The hormones they produce are critical for regulating metabolism, blood pressure, the body´s stress response, and electrolyte balance.

There are two main forms: primary adrenal insufficiency (also known as Addison disease), where the adrenal glands themselves are damaged, and secondary adrenal insufficiency, caused by insufficient stimulation of the adrenal glands by the pituitary gland in the brain.

Causes

The causes of adrenal insufficiency depend on the type:

Primary Adrenal Insufficiency (Addison Disease)

• Autoimmune disease: The most common cause in developed countries. The immune system mistakenly attacks and destroys adrenal tissue.
• Infections: Tuberculosis, HIV, and fungal infections can damage the adrenal glands.
• Tumors and metastases: Cancer spreading to the adrenal glands can impair their function.
• Adrenal hemorrhage or infarction due to blood clotting disorders or sepsis.

Secondary Adrenal Insufficiency

• Long-term corticosteroid use: The most common cause worldwide. Prolonged use of cortisone-based medications suppresses the body's own hormone production.
• Pituitary gland disorders (e.g., tumors, inflammation) that reduce production of ACTH, the hormone that stimulates the adrenal glands.
• Head trauma or pituitary surgery affecting hormone regulation centers in the brain.

Symptoms

Symptoms of adrenal insufficiency often develop gradually and can be non-specific at first. Common symptoms include:

• Persistent fatigue and exhaustion, even after adequate rest
• Dizziness, especially when standing up (orthostatic hypotension)
• Low blood pressure
• Weight loss and decreased appetite
• Nausea, vomiting, and abdominal pain
• Muscle weakness and joint pain
• Salt craving
• Mood changes, irritability, and depressive episodes
• In primary insufficiency: skin hyperpigmentation (darkening of skin folds, scars, and mucous membranes)

Adrenal Crisis

In severe cases, a life-threatening adrenal crisis (also called Addisonian crisis) may occur. This is characterized by a sudden and extreme drop in blood pressure, severe vomiting, confusion, and shock. An adrenal crisis is a medical emergency requiring immediate treatment.

Diagnosis

Diagnosis is based on clinical assessment, laboratory tests, and stimulation tests:

• Blood tests: Measurement of morning cortisol levels (when cortisol is naturally highest) and ACTH levels to distinguish between primary and secondary forms.
• ACTH stimulation test (Synacthen test): Synthetic ACTH is administered and the adrenal glands are tested for their cortisol response. An inadequate rise in cortisol confirms adrenal insufficiency.
• Electrolytes: Low sodium and high potassium levels can indicate primary adrenal insufficiency.
• Imaging: CT or MRI scans of the adrenal glands and pituitary gland to identify underlying causes.
• Autoantibody testing: Detection of antibodies against adrenal cortex tissue in suspected autoimmune cases.

Treatment

Since adrenal insufficiency is usually a lifelong condition, treatment focuses on replacing the hormones that the adrenal glands can no longer produce adequately:

Hormone Replacement Therapy

• Hydrocortisone (cortisol replacement): Taken 2 to 3 times daily to mimic the body's natural cortisol rhythm.
• Fludrocortisone (aldosterone replacement): Required only in primary adrenal insufficiency to maintain proper fluid and electrolyte balance.

Stress Dosing

Patients must increase their medication dose during physical or emotional stress, such as illness, surgery, or injury. This is called stress dosing or sick-day rules, and it is essential to prevent an adrenal crisis.

Emergency Preparedness

Patients with adrenal insufficiency should carry a medical alert card and an emergency kit containing injectable hydrocortisone for use in acute situations. Friends, family members, and caregivers should also be trained on how to administer emergency injections.

Living with Adrenal Insufficiency

With appropriate treatment and education, most people with adrenal insufficiency can lead normal, active lives. Regular medical follow-up, consistent medication adherence, and awareness of crisis warning signs are essential. Patient education programs and support groups can significantly improve quality of life.

References

1. Bornstein, S. R. et al. - Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology and Metabolism, 2016.
2. Arlt, W. - The approach to the adult with newly diagnosed adrenal insufficiency. Journal of Clinical Endocrinology and Metabolism, 2009.
3. World Health Organization (WHO) - Endocrine disorders: adrenal gland diseases. WHO Health Topics, 2022.